Day: November 28, 2012

Building a MIDI device is always a great microcontroller project, and nearly everyone has an old toy keyboard lying around in the back of a closet or in the basement. [JenShen] decided to take one of these toy keyboards and build a MIDI keyboard.

The keyboard [JenShen] used was a simple Casio keyboard with built-in voices. After tearing out the guts of the keyboard, the only thing that remained is the row of push buttons underneath the keys. These buttons were laid out in a row/column matrix, so [JenShen] needed to decode this matrix before sending the result to an Arduino for processing.

A 74HN595 shift register was used to read the 8 rows of buttons underneath the keys, while the rows were tied to different input pins on the ‘duino. This allowed [JenShen] to scan the keyboard matrix with an Arduino and generate MIDI notes and send them to other synths.

In the video after the break, you can check out [JenShen]’s circuit and code that allowed him to turn a toy keyboard into a proper 32-note MIDI keyboard. It’s not velocity sensitive, but he says he’ll show everyone how to accomplish that in a future post.

This unique electronic instrument combines a chopped up guitar and a hacked apart glockenspiel with an Arduino. [Aaron]’s Glockentar consists of guitar hardware and glockenspiel keys mounted to a wood body. Solenoids placed above the keys actuate metal rods to play a note.

Under the hood, an Arduino connects the pieces. The conductive pick closes a circuit, which is a digital input into the Arduino. This actuates the corresponding solenoid to play the glockenspiel key, and sends a character to a computer over serial.

On the computer, an openFrameworks based program creates lighting that is projected onto each string. MadMapper is used for projection mapping, which maps the openFrameworks output to each string. Video is passed between applications using the Syphon framework.

[Aaron] has provided a write up that goes into details, including the Arduino and openFrameworks source for the project. There’s also a video overview and demo of the Glockentar after the break.